Comment 5 for bug 1822179

Daniel, I don't believe this bug report is a duplicate of the bug you mentioned. After upgrading from 18.10 to 19.04, I see the same issue where I have my expected background when I login, and after I resume from sleep my background is a solid white or black colour. I cannot change the background if I try via the settings menu.

I do not experience any of the graphical issues mentioned in the bug you linked. The desktop, browser and applications are totally normal apart from not having the background I set for my lock screen and desktop.